A technology is known for generating a stereogram for displaying a stereoscopic video image from stereo images that are captured with a plurality of image capturing devices. The stereo images referred to herein are, for example, a set of two images with a given parallax. A digital camera, a camera provided to a portable terminal device, and a camera provided to a personal computer (PC) are examples of image capturing devices.
Stereoscopic video image scenes may have a flaw in that users feel uncomfortable with a scene where an object contained in a stereoscopic video image suddenly moves due to a sudden movement of the image capturing device or a scene where an object close to the image capturing device moves.
It is assumed that one of the reasons users feel uncomfortable is that the parallax is too large. Thus, technologies for reducing user discomfort have been proposed. For example, a device that displays images performs block matching when performing image decoding and detects similar blocks between stereo images. Such a device use the detected blocks to calculate the amount of parallax and displays a three-dimensional or two-dimensional screen according to the amount of parallax. In another example, a device that displays a stereoscopic video image calculates the level of fatigue a user has and announces the risk when the calculated level of fatigue is equal to or larger than a given value.
Patent Document 1: Japanese Laid-open Patent Publication No. 11-355808
Patent Document 2: Japanese Laid-open Patent Publication No. 2011-205702
However, the above-described conventional technology has a problem in that the load is heavy when processing is performed by a device that displays images. Specifically, such a device performs block matching processing, which has a heavy processing load. For this reason, the load is heavy when processing is performed by a device that displays images. Block matching processing may be performed by a device that performs image encoding processing.